Subunit and polysaccharide-conjugated vaccines
Subunit vaccines are a foundation of modern vaccinology. By containing only the essential components of a pathogen, such as purified proteins, polysaccharides, conjugates or outer-membrane vesicles (OMV), they offer a superior safety profile compared to whole-organism platforms.
Your partner for subunit and polysaccharide-conjugated vaccines
These vaccines are widely used to prevent bacterial infections like Haemophilus influenzae type b, pneumococcal and meningococcal diseases, where polysaccharide-conjugated antigens play a central role. The complex formulations of thes vaccine types introduce analytical challenges, such as variable conjugation ratios, heterogeneous mixtures and difficult matrices containing often formulation adjuvants. That’s why advanced analytical strategies are essential to ensure product quality and consistency.
At Quality Assistance, we support your subunit vaccine development with dedicated analytical solutions. Whether you're working on protein-based vaccines, polysaccharide conjugates or multivalent formulations, our expert team helps you guarantee the identity, purity, potency, safety and integrity of your product, at every stage your development.
Analytical services for subunit vaccines
To support the development of your subunit vaccine, we implement a broad spectrum of specific analytical methodologies to guide your decision-making. Our services include:
PROTEIN / MODIFIED TOXIN / VIROSOME
| Mass distribution profile | MS (ESI-QTOF / MALDI-TOF) |
|---|---|
| Structural integrity | CD / FT-IR |
| Isoforms | icIEF / (U)HPLC (IEX, RP, SEC, HIC) / 2D gel / Peptide mapping / MS |
| Aggregation / Fragments / Particle size distribution | SEC-(U)HPLC (UV, RI, MALS) / AF4 / cGE / DLS / SDS-PAGE / Imaging Particle Analysis |
| Glycosylation pattern | UPLC (FLUO, ESI-QTOF) / MALDI-TOF / CE (LIF) / GC (MS) |
| Disulphide bridges | Peptide mapping (UPLC-UV/MS) / cGE / SDS-PAGE |
| Free thiols | Fluorescence (NPM) / UV (Ellman, DTNB) |
| Degradation patterns (including Met oxidation / Asn deamidation) | IEX / RP-(U)HPLC / SE-(U)HPLC / SDS-PAGE / (U)HPLC (MS) / CE (icIEF, cGE) / 2D gel |
| Protein quantity | BCA / Lowry / Bradford / UV / (U)HPLC (UV, Fluo) |
|---|---|
| Absolute protein content determination | ICP-MS (S, isotope dilution) |
| Determination of extinction coefficient | UV + ICP-MS (S, isotope dilution) / UV |
| Immunoassays / Antigenicity | ELISA / ECL (MSD) / Immunodiffusion (RID) / Luminex / SPR (Biacore) / BLI (Octet) / FACS |
| Phospholipid content and identity | (U)HPLC (MS) |
|---|---|
| Size of virosomes | DLS / SEC-(U)HPLC (UV/MALS) / AF4 / Imaging Particle Analysis |
POLYSACCHARIDES
| Immunological characterisation | ELISA / Luminex / ECL (MSD) |
|---|
| Biochemical markers (e.g. O-acetyl / Sialic acid) | HPAEC (conductimetry) / Colometric assay / (U)HPLC (fluo) |
|---|---|
| Molecular size distribution | SEC-(U)HPLC (RI, MALS) / AF4 (RI, MALS) |
| Residual protein content | BCA / Lowry / Bradford / UV / ELISA |
| Specific rotation | Optical rotation |
| Counterion content (e.g. Na+, Ca2+) | ICP (OES/MS) / HPAEC (conductimetry) |
| Polysaccharide content | Colorimetric assay / (U)HPLC (Fluo, RI) / GC (FID, MS) |
|---|
CONJUGATES
| Immunological characterisation | ELISA / Luminex / MSD |
|---|
| Molecular size distribution | SEC-(U)HPLC (RI, MALS) / AF4 (RI, MALS) |
|---|---|
| Free polysaccharide content | Colorimetric assay / (U)HPLC (Fluo, RI) / GC (FID, MS) / ELISA |
| Free protein content | BCA / Lowry / Bradford / UV / ELISA |
| Polysaccharide content | BCA / Lowry / Bradford / UV / ELISA |
|---|---|
| Protein content | BCA / Lowry / Bradford / UV |
| Antigen / conjugale content | ELISA / Luminex / ECL (MSD) / Elispot |
We cover all major vaccine technologies
General vaccine testing services
Subunit vaccine development also demands a full complement of general testing. We ensure your product meets the highest standards of safety and efficacy through:
- Full batch release testing (including sterility, endotoxin and pyrogenicity)
- Method development, validation and transfer (adhering to cGMP guidelines)
- Comprehensive stability studies (to define shelf-life and storage conditions)
Related services
Cross-analytical services
The analytical expertise applied to subunit vaccines is also relevant to protein-based biotherapeutics. By bridging vaccine and therapeutic applications, we ensure consistent, compliant support across diverse development pipelines.
See the complete analytical services for protein-based therapeutics
Ready to move forward ?
Developing subunit vaccines, whether protein-based, polysaccharide or conjugates, requires integrated expertise in both protein and carbohydrate analytics. At Quality Assistance, we combine these capabilities on a single site ensuring clarity, compliance and confidence.
Need to prove your vaccine's Critical Quality Attributes (CQAs) to regulators? Talk to our experts today to build a tailored analytical strategy that drives your IND/BLA submission forward.
Get in touch with our team of experts